Circuit interrupter



April 20 1926;

y A. BESCHNITT cmcuxw'm'rsnnurwnn Filed May 14. 1925,

- Im/ehtor: *Nberb Beschni'tlt, by

His 'M'xofney Patented Apr. 20, 1926.

ALBERT 'GIIOB TU GENERAL ELEQTR IC COM- PANY, A CORIGRATIOEI YORK.

CIRCUIT INTERRUP I ER.

Application filed May 14, i923.

To LZZ whom it may concern:

Be it known that 1, finance? BESCHNITT, a citizen of the German Realm,residing at Berlin. Germany, have invented certain new and usefulImprovements in Circuit Interruptcrs, which the "Following is aspecilication.

One of the objects of the invention is to provide an improvedinterrupter for electric circuits which will positively and quicklyinterrupt the controlled circuit in response to a predeterminedcondition, such, for instance, as an overload condition.

A further object of the invention is to provide an impr Ted interrupterwhich is magnetically held closed and magnetically opened.

2 still further object of the invention is to provide an improvedinterrupter which does not require the use of triggers, latches and thelike for holding the switch contact niechanisn'i in the closed position.

A. still further object of the invention is toprovide an interrupterwhic iis held closed by an electi'oinagnet having a shunt winding andopened by means responsive to the current in the controlled circuit, thearrangem nt being such that the flux of the shunt winding isautomatically shifted to assist in opening the controlled circuit.

Another object of he invention is to provi .0 an improved circuitinterrupter in which a plurality o1 s itch contact menihers are arrangedto be connected in series relation in a circuit to be controlled and theswitch members are held in the closed position by a single clectroinag"et having a shunt holding coil and the s ch members are operated to theopen position under the control of series winding which opposes thenormal efilect of the shunt winding. Tl" and other objects of theinvention as either apparent to those skilled in the art or as will hepointed on fully hereiiaiter are attained in the electromagnetic vitchillustrated in the accompanying crawings.

deterring to the accoi'npang'ing drawings, Fig. 1 shows veryd1agrannnatically a cirinterrupter in ordance with the invention, thesingle switch IDGIHlJOY of the interrupter being magnetically held inthe clo ed position; 2 is a very diagrammatic view showing the relativepositions of the parts when the circuit in alter is in Serial No.638,?59.

the open position; Fig. 3 is a diagrammatic view of a double polecircuit breaker in accordance with the invention, with the switchcontact members in their respective closed positions; and F a: is a VlQWshowing the relative positions of the parts of the switch illustrated inFig. 3 when the switch membe are in their respective open positions.Referring to the drawings, Figs. 1 and 2, the movable switch member 10is adapted to make engagement with the stationary switch contact 111 asto complete the circuit controlled by the switch. 'The switch member 10is under the control of electromagnetic means having a magneticstructure comprising the armature l2'which is pivotally mountedintermediate its ends and tho E-shapedmagnetic structure 13. Thearmature l2 and the switch member controlled thcrehy are held in theirrespective closer p sitions in response to the magnetic flux set up bythe shunt winding 14-. This shunt winding 14- is disposed on the middlele ot' the i i-shaped magnetic structure, and it will be oh er thatwhile the magnetic structure provides two multiple connected 1 paths,the swit n member is held in the closed pos on oy reason of the flux inthe the paths. The pivotal upper portion or moun ing of the armature1'22 is preferably opposite the middle leg or the common part or the twopaths for the magnetic flux of when the armashown and the theelectronisgnet, so that med the magnetic tnre is in the ion shunt wind ve L the up portion of the predominates orer 'ie magnetic is a mature'ill be hell in the bias of the spring open theiwritch. he switch. isiagiieticaly opened under ontrol of the ries 'nding 16 which v either beinclut e v led directly in the circontrolled by the svitch or energizedesponsively to the current in the controlled circuit, as will heunderstood by those sl-zilled in the art. The series winding is disposedon the lower leg of the Eshaped magnetic structure and since thiswinding embraces the lower the multiple connect-ed paths of the magneticstructure, it is in close inductive relation with the shunt winding Aslong as the attractive force of the magnetic flux of the shunt winding14: acting is interrupted,

the magnetic pull of the flux set up by the series winding predominatesover the magnetic pull set up by the shunt winding, the switch will beopened, thereby protecting the controlled circuit from abnormal currenconditions. The arrangement is preterably such that the direction of theflu set up by the shunt winding and the direction of the flux setup bythe series winding through the common part of the multiple connectedpaths is in the same direction,

so that when the armature 12 starts to move away from the closedposition under the control of the series winding so as to therebyincrease the air gap 17 and decrease the air gap 18, the flux of theholding winding 14 will diminish through the upper portion of themagnetic paths and will be shifted so as to pass through the lowerportion of the magnetic paths and thus assist the series winding and thebiasing spring 15 in opening the switch. This is an important feature ofthe invention, for the reason that the holding magnet serves to normallyhold the switch member in the closed position as long as conditions inthe controlled circuit are normal, but when the conditions in thecontrolled circuit become abnormal, the flux of the holding magnet ismade ellective to assist in the opening of the switch. Due to theinductive relation between the series winding 16 and the shunt winding1e, a very rapid shitting o1 the flux ofthe shunt winding is etlectedupon a rapid increase in the current through the series winding and avery quick interruption of the controlled circuitis thereby efitected.

By reference to Fig. 2 it will be seen that the flux set up by theholding magnet through the upper portion of the magnetic circuit ismaterially less than the flu): set up through the lower portion of themultiple connected magnetic paths. The flux: is indicated by the dot anddash lines with the arrows indicating the direction of the fluxes, in amanner which will be well understood by those skilled in the art. litwill be understood, of course. that after the switch contacts haveopened and the controlled circuit has been interrupted, the spring 15will be effective to complete the opening movement of the switch, sincewhen the circuit the pull set up by the series winding will cease. Itwill .lso hen-Cited that the flux lines as indicated in Fig. 2 are notnecessarily of the exact relative values as shown after the switch hasopened, it be ing the intention of this figure to rather indicate thedistribution of the fluxes while the switch is in the act of opening.

By reference to Fig. 3 it will be observed that my invention isapplicable to an arrangement in which two switch m mbers connected inseries in the controlled circuit are controlled by a commonelectromagnetic device in accordance with the invention, as explained inconnection with Figs. 1 and 2. By reference to Fig. 3, it will be seenthat two pivotally mounted arn'iatures 12 and 12 are provided and thatthese ari'natures, together with the magnetic pole pieces 19 and 20,form a magnetic structure which is essentially the same as the magneticstruc ture of the switch illust ated in Figs. 1 and Each of thearmatures 12 and 12" is biased to the open position by its respectivespring as indicated, and the shunt winding 1 3 is effective to hold thetwo armaturcs and their controlled switch members in their respectiveclosed positions as long the flux set up by this shunt winding throughthe upper portion of the multiple connected magnetic paths predominatesover the flux set up by the series winding 16 through the lower portionof the magnetic paths. The operation of this form of my invention is inprinciple the same as the operation of the arrangen'ient shown in Figs.1 and 2, and it is believed that "from the previous description given,it will be understood by those skilled in the art that the switchmembers will be magnetically held in their closed positions untilthetiux set up by the series winding predominates so as to attract thelower portions 01": the armatures 12 and 12 toward each other so as tosimultaneously interrupt the controlled circuit at both interruptinggaps. When t 1e effect of the series winding predominates the flux ofthe shunt winding will be shifted so as to assist in opening the switchmembers in the same manner as explained in Figs. 1 and 2. lVh n theswitch is thus opened, the parts will be in their relative positions, asshown in Fig. 4, and it will be understood that the direction andmagnitude of the flux lines indicated in this figure are to be taken asrepresenting the conditions while the.

away from their toward their reswitch members are moving respectiveclosed positions spective open positions.

It will be observed that my improved electro-magnetically controlledswitch or circuit interriq'it-er is arranged to be magnetically heldclosed and magnetically opened, and that there is no necessity for theuse of triggers, latches and the like which are troublesome and likelyto get out of repair, and which are also objectionable for the reasonthat delays in the opening of the conto open the switch,

lot

trolled circuit are introduced thereby. It will also be observed thatthe holding winding is in close inductive relation with the serieswinding in order to render the former eflective to assist the serieswinding in the by Letters Patent of the United States, is

1. A circuit interrupter comprising a switch member bias-ed to the openposition, an electromagnet having a centrally pivoted armature and ashunt winding acting on one end of the armature for holding the switchmember in the closed position, and means responding to the current inthe controlled circuit acting on the other end of the armature forshifting the magnetic flux of the shunt winding to the said other end ofthe armature, to permit the switch member to open the controlledcircuit.

2. A circuit interrupter comprising two switch members arranged. to beconnected in series in an electric circuit to be controlled, anelectromagnet having a separate pivotally mounted armature connected toeach of said switch members and a shunt winding tor holding the saidswitch members in their closed positions, and means responsive to thecurrent in the controlled circuit for attracting the said armatures toopen the controlled circuit.

A circuitinterrupter comprising two switch members biased to their openposilions and arranged to be connected in series in an electric circuitto be controlled, an electroiuagnet having a separate pivotally mountedarmature connected to each of said switch members and a shunt windingfor setting up a flux to hold the said switch members in their closedpositions, and means responsive to the current in the controlled circuit"for shifting the magnetic flux of the shunt winding to assist the biasof the said switch members to their open positions' *l. A circuitinterrupter comprising a switch member, an electromagnet having apivotally mounted armature and a shunt winding disposed on. a part ofthe magnetic structure of the said electromagnet opposite the pivot ofsaid armature and cooperating with one end of the armature for holdingthe said switch member in the closed position, and a series windingdisposed with respect ,to the said arnjiature to produce a this actingsubstantially entirely on the other .end of the said armature foreffecting the interruptioiro'f the controlled circuit in response to thecurrent through the series winding.

5. A circuit interrupter comprising a switch member, an electromagnethaving a centrally pivoted armature and a shunt winding disposed on apart of the magnetic structure of the said electroinagnet opposite thepivot of said armature and co-operating with one end of the arn'iaturefor holding the said switch member in the closed position, and a serieswinding acting upon the other end of said armature for shifting themagnetic flux of the said shunt winding to assist the iiux of the serieswinding to effect the interruption of the controlled circuit inaccordance with the current through the series winding.

6. A circuit interrupter comprising a switch member, an electromagnethaving a v magnetic structure with two multiple connected paths for theflux of the electromagnet and a shunt winding disposed on the commonpart of the said paths for setting up a magnetic flux through one ofsaid paths for magnetically holding the said switch member in the closedposition, and a series winding disposed in inductive relation with saidshunt winding on the other of the said paths to set up a flux throughthe said common path in the same direction as the flux of the shuntwinding for magnetically operating the switch member from the closedposition towa d the open position.

7, A circuit interrupter comprising a pivotally mounted switch member,and an electromagnet having a magnetic structure with two multipleconnected paths for the flux of the electromagnet, the common part ofthe said paths disposed substantially opposite the pivotal mounting ofthe said switch member, a shunt winding disposed on the said common partof the said paths for setting up a magnetic flux through one of saidpaths on one side of the said pivotal mounting of the switch member formagnetically holding the switch member in the closed position, and aseries winding for magnetically operating the switch member from theclosed postion toward the open position, the said series windingdisposed in inductive re lation with said shunt winding on the other ofsaid paths so as to set up a flux therein which is in the same directionthrough the said common part of the paths as the flux of the said shuntwinding.

8. A circuit interrupter comprising a switch member and an eleotromagnethaving a centrally pivoted armature, a magnetic structure cooperatingtherewith to form multiple connected flux paths through opposite ends ofsaid armature, a shunt winding disposed on the common part of said pathspart as the flux of the shunt winding for for setting up a magnetic fluxthrough one magnetically operating the switch member 10 of said pathsfor magnetically holding the from the closed position toward the opensaid switch member in the closed position, position.

- and a series winding disposed in inductive In witness whereof, I havehereunto set relation with said shunt winding on the my hand this Qthday of April, 1923. other of said paths to set up a flux in the samedirection through the said eonnnon ALBERT BESOHNITT.

